Introducing the brain: sleep and anesthesia differences (Introduction)

by David Turell , Saturday, September 02, 2023, 16:21 (238 days ago) @ David Turell

Quite different:

https://www.cell.com/neuron/fulltext/S0896-6273(23)00618-9?dgcid=raven_jbs_aip_email#se...

Decreased complexity and connectivity, with increased variability when unconscious.

Changes were more pronounced during propofol-induced general anesthesia than sleep.

During sleep, changes were homogeneously distributed across the human brain.

During anesthesia, substantial prefrontal disconnection is related to lack of arousability.

Summary:

"What happens in the human brain when we are unconscious? Despite substantial work, we are still unsure which brain regions are involved and how they are impacted when consciousness is disrupted. Using intracranial recordings and direct electrical stimulation, we mapped global, network, and regional involvement during wake vs. arousable unconsciousness (sleep) vs. non-arousable unconsciousness (propofol-induced general anesthesia). Information integration and complex processing we`re reduced, while variability increased in any type of unconscious state. These changes were more pronounced during anesthesia than sleep and involved different cortical engagement. During sleep, changes were mostly uniformly distributed across the brain, whereas during anesthesia, the prefrontal cortex was the most disrupted, suggesting that the lack of arousability during anesthesia results not from just altered overall physiology but from a disconnection between the prefrontal and other brain areas. These findings provide direct evidence for different neural dynamics during loss of consciousness compared with loss of arousability."

Comment: these differences are not surprising.